Guess I'll throw the pics of my .204 Ruger Belted Magnum up again...





This pretty much caused a similar event as mentioned in the original post minus the damaged bolt head and BAS screw threads. Where the case rim is blown out in the second photo is the area that pushed out into the extractor slot in the bolt head, pushing the extractor outward accordingly. That portion of the case head was actually retaining the spring and detent ball, and the extractor was pushed out far enough to prevent the bolt from being able to turn. Ejector was jammed back in it's pocket as you would expect. Had to disassemble the bolt in the rifle and then pop the case out with a cleaning rod. Primer was not pierced.

Still not sure what happened with this one as I was loading 40gr V-max's with 28.2 grains of Varget, which is a compressed load and just 0.1 grain over published max. I didn't get any pressure signs with this load when doing my ladder test, and I'd shot several groups with this same load just prior to shooting this round. I can only presume that I had a bit of powder hang up in my powder measure from the previous round that caused this one to be slightly over. Given the size of Varget and it already being a compressed load you would think I would have noticed the powder sitting slightly higher in the neck if that were the case, but maybe not.